Conventionally, digital cameras of this type record video images formed on a CCD on a memory card as a plurality of still images, read desired still images selectively from the memory card as required, and display them on an LCD attached to the camera body or on a home television set or personal computer monitor connected externally.
With such digital cameras, generally image data resulting from the images of subjects picked up is recorded in files classified by shooting modes on a memory card based on serial numbers which represent the order of shooting as well as on the date/time of shooting and the like.
When a user wants to review, on a digital camera, a desired image in an image group recorded on a memory card, the user searches for the desired image visually by displaying the image group read from the memory card on a liquid crystal monitor in full screen on a image by image basis or as an index screen in units of several images.
However, this method of searching for the desired image while displaying images one by one on a liquid crystal monitor is practical only when there are a relatively small number of photographic images. When there are a very large number of photographic images such as when a large capacity memory card is used, it is very difficult for the user to search for a desired image by checking a huge number of images visually on a liquid crystal monitor.
To deal with this situation, actually a memory card taken out of a digital camera is mounted on a personal computer, or the digital camera is connected, for example, via a communications cable such as a USB (Universal Serial Bus) cable, and a plurality of files are often managed hierarchically using a directory corresponding to the memory card and presented on a display screen.
With a typical personal computer, when a memory card is mounted, the directory corresponding to the memory card is presented on the display screen either automatically or in response to a user action. Then, the directory is opened in response to a user action and a plurality of files contained in the directory are displayed.
The user can search for a file in a shooting mode which corresponds to a desired image among the plurality of files, open the file, select a desired image name from among images contained in the file, and thereby display the image which has the selected name on the display screen.
Among hierarchical file management methods which employ such directories, a method has been proposed recently which makes it easy to search for and edit images during playback by classifying the directories, for example, into “Portraits,” “Group Photos,” “Scenery,” “Close-Ups,” “Sports,” “Automatic Selection,” etc. according to the type of photographed subject, selecting one directory based on the user's selection during shooting or according to image pattern analysis based on results of photography, and attaching information about the directory to corresponding image data (see, for example, Patent Document 1).
Patent Document 1: Japanese Patent Laid-Open No. 6-78260 (pages 3 and 4, and FIGS. 3 and 5)
However, when a memory card containing image data to which directory information classified according to the type of subject is attached is mounted on a personal computer and played back, only directories are presented on the display screen, and relationship between directories and data contained in them must be specified by the user.
There is no problem only if desired application software has been installed on the user's personal computer. Otherwise, the user must purchase such application software or create an executable application program for himself/herself, which constitutes a heavy burden because of required time and effort.